GlossaryAdvanced
TRIN (Arms Index)
A market-breadth indicator comparing the ratio of advancing-to-declining issues against the ratio of advancing-to-declining volume.
TRIN (also called the Arms Index), developed by Richard Arms, compares the ratio of advancing-to-declining issues against the ratio of advancing-to-declining trading volume, combining both the number of assets moving and the volume behind that movement into one reading.
A TRIN reading above 1 generally suggests declining volume is outpacing declining issue count (more selling pressure than the simple advance/decline count alone would suggest), and below 1 generally suggests the opposite. See Kaavon's dedicated TRIN article for the full calculation and its common interpretation.
Examples
- A TRIN reading above 1 can occur even on a day with more advancing issues than declining ones, if declining volume is disproportionately heavy.
- TRIN combines issue breadth and volume breadth into a single reading, rather than measuring either in isolation.